Chapter 12: Communities and Populations

If you saw the movie Finding Nemo, then you probably recognize this fish. It’s known as a clownfish, and it’s swimming near the tentacles of an animal called a sea anemone. The sea anemone kills prey by injecting poison with its tentacles. For some reason, the anemone doesn’t harm the clownfish, perhaps because the fish has a coating of mucus that helps disguise it. But why does the clownfish “hang out” with the sea anemone? One reason is for the food. The clownfish eats the remains of the anemone’s prey after it finishes feeding. Another reason is safety. The clownfish is safe from predators when it’s near the anemone. Predators are scared away by the anemone’s poison tentacles. In return, the clownfish helps the anemone catch food by attracting prey with its bright colors. Its feces also provide nutrients to the anemone. The clownfish and anemone are just one example of the diverse ways that living things may help each other in nature. You will learn more about species interactions such as this when you read this chapter.